Motorcycle frame



FIG. 1 is a perspective view of a motorcycle frame embodying the design of the present invention.

FIG. 2 is a right side elevational view of the motorcycle frame illustrated in FIG. 1.

FIG. 3 is a left side elevational view of the motorcycle frame illustrated in FIG. 1.

FIG. 4 is a front elevational view of the motorcycle frame illustrated in FIG. 1.

FIG. 5 is a back elevational view of the motorcycle frame illustrated in FIG. 1.

FIG. 6 is a top view of the motorcycle frame illustrated in FIG. 1; and,

FIG. 7 is a bottom view of the motorcycle frame illustrated in FIG. 1.

The portions shown in broken lines form no part of the claimed design. 

The ornamental design for a motorcycle frame, substantially as shown and described. 